A chip test apparatus generally includes probes, a peripheral circuit and a circuit of special function. The peripheral circuit is used to measure performance parameters of the chip and the circuit of special function is used to apply special treatment to the chip. In the prior art, the probes, the peripheral circuit and the circuit of special function of a test apparatus are arranged on the same circuit board, namely the probes, the peripheral circuit and the circuit of special function of a test apparatus are arranged in the same plane. As a result, the density of components on the circuit board is high, and interference between the components is likely to occur. Moreover, the entire test apparatus must be discarded and replaced by a new one even when only one circuit on the circuit board is damaged, causing a high testing cost.
Take fuse reconditioning as an example, in order to optimize the performance of a chip, reconditioning of the chip fuses is often needed to select suitable internal circuit modules. Fuse reconditioning includes the steps as follows: measure parameters of the chip; select the fuses to be reconditioned based on the measurement results of the chip parameters; melt the selected fuses. Accordingly, a test apparatus for fuse reconditioning includes probes, a peripheral circuit for measuring chip parameters, and a fuse melting circuit (circuit of special function) for melting a selected fuse.
FIG. 1 illustrates a test apparatus for fuse reconditioning of the prior art. The test apparatus includes a circuit board 110, probes 120, a peripheral circuit 130 and four fuse melting circuits 140. In this example, the test apparatus for fuse reconditioning includes four fuse melting circuits 140 (namely four circuits of special functions) so that fuse reconditioning can be applied to four chips at the same time. The circuit board 110 has a round hole formed in it. The probes 120 are arranged in the round hole via a probe mount 160. The peripheral circuit 130 and the four fuse melting circuits 140 are all arranged on the circuit board 110. The circuit board 110 also has probe pins 150 arranged on it, and the number of probe pins 150 is equal to the number of probes 120. Each probe pin 150 is electrically connected to a probe 120. In this example, the probe pins 150 are arranged in a circle surrounding the probes 120. The peripheral circuit 130 and the four fuse melting circuits 140 are electrically connected to the probe pins 150 through wires (not shown in FIG. 1), and thus electrically connected to the probes 120. Those probes 120 electrically connected to the peripheral circuit 130 are used to measure chip parameters, while those probes 120 electrically connected to the fuse melting circuits 140 are used to melt fuses of the chips.
In the test apparatus for fuse reconditioning of this example, five circuits (a peripheral circuit 130 and four fuse melting circuits 140) are arranged on the same circuit board 110, resulting in a relatively high density; further, all the probes 120 are arranged in the same circle (with only small gaps between neighboring probes), so that interference between the probes is likely to occur; additionally, even when only one of the five circuits is damaged, the test apparatus must be discarded and be entirely replaced by a new test apparatus for fuse reconditioning, leading to a high testing cost.